1. Field of the Invention
The present invention relates to a wiring structure between a plurality of pads and a plurality of internal circuits, and more particularly, to electrostatic discharge breakdown of an internal element in the wiring structure.
Priority is claimed on Japanese Patent Application No. 2009-250345, filed Oct. 30, 2009, the content of which is incorporated herein by reference.
2. Description of the Related Art
Japanese Unexamined Patent Application, First Publication, No. 2007-27401 discloses a wiring structure of power supply wirings which connect a plurality of power supply pads to a plurality of internal circuits in a semiconductor device, and discloses an effective wiring structure for preventing a power supply voltage supplied to an internal circuit from being dropped due to parasitic resistance of a power supply wiring and preventing a ground voltage from being raised.
In a general semiconductor device, a protection circuit for protecting an internal circuit from electrostatic discharge breakdown when an external overvoltage is applied to a power supply pad or an IO pad is provided around the power supply pad or the IO pad.
However, no protection circuit is disclosed in Japanese Unexamined Patent Application, First Publication, No. 2007-27401.